"People around him are worried about how Johnny is doing because he and Vanessa seem so fractured right now," alleges a source. "Their relationship is heading toward the end."

The cooler-than-cool twosome, who live an ultra-low-key life in France and the Hollywood Hills with kids Lily, 12, and Jack, 9, have supposedly been "arguing constantly."

"Johnny has started reaching out to lawyers, probably to quietly discuss how to get out of the relationship," conclusion-leaps the insider. "They're not married, but they've been together for years and have kids together so it isn't as easy as just breaking up."

But don't give up on true love just yet: Depp, 48, and Paradis, 39, reportedly spent New Year's Eve together with their family in Los Angeles.

Depp's rep did not respond to our request for comment on the rumblings of trouble.

The rumors follow Star's recent contention that the ageless, A-list eccentric has been experiencing a "mini-midlife crisis."

"I don't know how it works, but it does all work beautifully," the actor said of his home-life back in October. "Our family is not conventional. It's sort of symmetrical and asymmetrical and poetic and funny."

And designed to handle the occasional time out.

"We understand that, if we want our relationship to continue, we must give each other space, allow each other to go off on our own, and trust each other," Paradis, 39, told Marie Claire in 2010. "Not everyone is lucky enough to be given space and trust."

As we hope for the best, let's take a look back at Johnny and Vanessa's love affair ...